The present invention pertains to a wear assembly for use on various kinds of earth working equipment.
In mining and construction, wear parts are commonly provided along the digging edge of excavating equipment such as buckets for dragline machines, cable shovels, face shovels, hydraulic excavators, and the like. The wear parts protect the underlying equipment from undue wear and, in some cases, also perform other functions such as breaking up the ground ahead of the digging edge. During use, the wear parts typically encounter heavy loading and highly abrasive conditions. As a result, they must be periodically replaced.
These wear parts usually comprise two or more components such as a base that is secured to the digging edge, and a wear member that mounts on the base to engage the ground. The wear member tends to wear out more quickly and is typically replaced a number of times before the base must also be replaced. One example of such a wear part is an excavating tooth that is attached to the lip of a bucket for an excavating machine. A tooth typically includes an adapter secured to the lip of a bucket and a point attached to the adapter to initiate contact with the ground. A pin or other kind of lock is used to secure the point to the adapter. Improvements in strength, stability, durability, safety, and ease of installation and replacement are desired in such wear assemblies.
The present invention pertains to a wear assembly for use on various kinds of earth working equipment including, for example, excavating machines and ground conveying means.
In one aspect of the invention, the wear assembly includes a base with a supporting portion, a wear member with a cavity into which the supporting portion is received, and a lock to releasably secure the wear member to the base. The supporting portion is formed with top and bottom recesses that receive complementary projections of the wear member. These recesses and projections include aligned holes so as to receive and position the lock centrally within the wear assembly and remote from the wear surface. This arrangement shields the lock from abrasive contact with the ground and lessens the risk of ejection or loss of the lock.
In another aspect of the present invention, the wear assembly includes a base with a supporting portion and a wear member with a cavity to receive the supporting portion. The fit between the supporting portion and the wear member includes stabilizing surfaces along each of the top, bottom and side walls in a unique configuration that creates a highly stable mounting of the wear member with improved penetrability.
In another aspect of the present invention, the wear member includes a wear indicator depression that opens in the nose-receiving cavity and is initially closed and spaced from the external wear surface, but which breaks through the wear surface when it is time to replace the wear member because of wear.
In another aspect of the invention, the wear member includes a hole for receiving the lock to secure the wear member to the base. The hole is defined by a wall that includes a retaining structure provided with an upper bearing surface and a lower bearing surface for contacting and retaining the lock against upward and downward movement in the hole. In one preferred construction, a passage is provided in the hole to enable a lock or lock component to fit into the hole as an integral unit and be positioned to contact the upper and lower bearing surfaces of the retaining structure.
In another aspect of the invention, the lock includes a mounting component provided with a securing structure for attachment within a hole in the wear member. The securing structure cooperates with a retaining structure within the hole to resist movement of the mounting component in and out of the hole during use. The mounting component defines a threaded opening for receiving a threaded pin that is used to releasably hold the wear member to the base. The separate mounting component can be easily manufactured and secured within the wear member for less expense and higher quality than forming the threads directly in the wear member. The mounting component can be mechanically held within the hole in the wear member to resist axial movement in either direction so as to avoid unintended loss of the lock.
In another aspect of the invention, the lock includes a mounting component received and mechanically secured into a hole in the wear member to resist axial movement, a locking component movably received in the mounting component to releasably secure a wear member to a base, and a retainer to prevent release of the mounting component from the wear member.
In another aspect of the invention, the lock includes threaded components that are mechanically secured to a hardened steel wear member. The lock component can be adjusted between two positions with respect to the wear member: a first position where the wear member can be installed or removed from the base, and a second position where the wear member is secured to the base by the lock. The lock is preferably securable to the wear member by mechanical means at the time of manufacture so that it can be shipped, stored and installed as an integral unit with the wear member, i.e., with the lock in a “ready to install” position. Once the wear member is placed onto the base, the lock is moved to a second position to retain the wear member in place for use in an earth working operation.
In another aspect of the invention, a lock for releasably securing a wear member to earth working equipment includes a threaded pin with a socket in one end for receiving a tool to rotate the pin. The socket includes facets for receiving the tool, and a clearance space in lieu of one of the facets to better avoid and clean out earthen fines from the socket.
The present invention pertains to a wear assembly for various kinds of earth working equipment including, for example, excavating equipment and ground conveying equipment. Excavating equipment is intended as a general term to refer to any of a variety of excavating machines used in mining, construction and other activities, and which, for example, include dragline machines, cable shovels, face shovels, hydraulic excavators, and dredge cutters. Excavating equipment also refers to the ground-engaging components of these machines such as the bucket or the cutter head. The digging edge is that portion of the equipment that leads the contact with the ground. One example of a digging edge is the lip of a bucket. Ground conveying equipment is also intended as a general term to refer to a variety of equipment that is used to convey earthen material and which, for example, includes chutes and mining truck beds. The present invention is suited for use along the digging edge of excavating equipment in the form of, for example, excavating teeth and shrouds. Additionally, certain aspects of the present invention are also suited for use along the expanse of a wear surface in the form of, for example, runners.
Relative terms such as front, rear, top, bottom and the like are used for convenience of discussion. The terms front or forward are generally used to indicate the normal direction of travel during use (e.g., while digging), and upper or top are generally used as a reference to the surface over which the material passes when, for example, it is gathered into the bucket. Nevertheless, it is recognized that in the operation of various earth working machines the wear assemblies may be oriented in various ways and move in all kinds of directions during use.
In one example, a wear assembly 14 in accordance with the present invention is an excavating tooth that attaches to a lip 15 of a bucket (
Adapter 19 includes a pair of legs 21, 23 that straddle lip 15, and a forwardly projecting nose 18. The intermediate adapter 12 includes a rearwardly-opening cavity 17 to receive nose 18 at the front end of adapter 19 (
Wear member 10, in this embodiment, has a generally wedge-shaped configuration with a top wall 20 and a bottom wall 22 that converge to a narrow front end 24 to engage and penetrate the ground during operation of the equipment (
The front end portion 30 of cavity 26 (
Stabilizing surfaces 34, 36 oppose and bear against complementary stabilizing surfaces 44, 46 on the nose 48 of base 12 (
Front end portion 30 of cavity 26 further includes side bearing surfaces 39, 41 to contact complementary side bearing surfaces 45, 47 on nose 48 to resist side loads (i.e., loads with a side component). Side bearing surfaces 39, 41 in cavity 26 and side bearing surfaces 45, 47 on nose 48 preferably axially extend substantially parallel to longitudinal axis 42 for greater stability in the mounting of wear member 10. These front side bearing surfaces 39, 41, 45, 47 cooperate with rear bearing surfaces that also resist side loads (as discussed below). In the preferred embodiment, the front bearing surfaces 34, 36, 39, 41 in cavity 26 are each formed with slight lateral concave curvature for better resisting shifting loads and loads from all directions. Front bearing surfaces 44-47 on nose 48 would have a complementary convex configuration. The front bearing surfaces in cavity 26 and on nose 48 could, however, be flat or formed with a different curvature.
Nose 48 of base 12 includes a rear or main portion 50 rearward of stabilizing surfaces 44, 46 of the front end 52 (
Central section 54 is defined by a top surface 58 and a bottom surface 60. Top and bottom surfaces 58, 60 preferably axially extend substantially parallel to longitudinal axis 42, but they could have a greater inclination. Top surface 58, on each side, blends into an inner surface 62 on side sections 56. Inner surfaces 62 are laterally inclined upward and outward from top surface 58 to partially define the upper part of side sections 56. Likewise, inner surfaces 64 are laterally inclined downward and outward from bottom surface 60 to partially define the lower part of side sections 56. Inner surfaces 62 are each laterally inclined to top surface 58 at an angle α of about 130-140 degrees to resist both vertical and side loading on wear member 10, and reduce stress concentrations during loading (
A central hole 66 is formed in central section 54 that opens in top and bottom surfaces 58, 60 (
Hole 67 in wear member 10 is defined by a wall 68 that preferably surrounds the lock 16 (
In a preferred embodiment, retaining structure 69 is essentially a continuation of wall 68 that is defined by a first relief 77 above or outside of the retaining structure 69, a second relief 79 below or inside of the retaining structure 69, and passage 75 at the distal end 81 of retaining structure 69. Reliefs 77, 79 and passage 75, then, define a continuous recess 83 in perimeter wall 68 about retaining structure 69. The end walls 87, 89 of reliefs 77, 79 define stops for the positioning of lock 16. A recess 85 is preferably provided along an inside surface 91 of cavity 26 to function as a stop during the insertion of a mounting component of lock 16 as described below.
Cavity 26 in wear member 10 has a shape that complements nose 48 (
Lower projection 76 is preferably the mirror image of upper projection 74, and includes an inside surface 82 to oppose bottom surface 60, and side surfaces 84 to oppose and bear against inner surfaces 64. In cavity 26, then, inside surface 78 faces inside surface 82 with gap 86 in between the two inside surfaces 78, 82 that is slightly larger than the thickness of central section 54 of nose 48. The thickness (or height) of gap 86 is preferably within the middle two thirds of the overall thickness (or height) of the cavity (i.e., the largest height) 26 along the same lateral plane, and is most preferred within the middle 60% or less of the overall thickness of the cavity along the same lateral plane. Side surfaces 80, 84 are laterally inclined away from the respective inside surfaces 78, 82, and axially extending substantially parallel to the longitudinal axis 42 to define upper and lower rear stabilizing surfaces for the point. The front stabilizing surfaces 34, 36 cooperate with rear stabilizing surfaces 80, 84 to stably support wear member 10 on nose 48. For example, a downward vertical load L1 on the front end 24 of wear member 10 (
The bearing contact between side surfaces 80 and inner surfaces 62, and between side surfaces 84 and inner surfaces 64, resists both vertical loads and loads with lateral components (called side loads). It is advantageous for the same surfaces to resist both vertical and side loads because loads are commonly applied to wear members in shifting directions as they are forced through the ground. With the laterally inclined stabilizing surfaces, bearing between the same surfaces can continue to occur even if a load shifts, for example, from more of a vertical load to more of a side load. With this arrangement, movement of the point on the nose is lessened, which leads to reduced wearing of the components.
A hollow portion 88, 90 is provided to each side of each of the upper and lower projections 74, 76 in cavity 26 for receiving side sections 56 of nose 48 (
In the preferred construction, each sidewall 100 of nose 48 is provided with a channel 102 (
The opposite sides 98 of cavity 26 define projections 108 that complement and are received into channels 102. Projections 108 include bearing walls 110, 112 that oppose and bear against channel walls 104, 106 to resist vertical and side loading. Projections 108 preferably extend the length of sidewalls 98, but they could be shorter and received in only portions of channels 102. Bearing walls 110, 112 preferably match the lateral inclination of channel walls 104, 106, and axially extend substantially parallel to longitudinal axis 42.
While any opposing parts of the wear member 10 and base 12 may engage one another during use, the engagement of surfaces 34, 36, 44, 46, 62, 64, 80, 84, 104, 106, 110, 112 are intended to the primary bearing surfaces to resist both vertical and side loading. The contact of front wall 114 of cavity 26 against front face 116 of nose 48 are intended to be the primary bearing surfaces resisting axial loads (i.e., loads with components that are parallel to longitudinal axis 42).
Wear member 10 preferably includes laterally spaced recesses 123, 125 in top wall 20 and corresponding laterally spaced recesses 127, 129 in bottom wall 22 at the rear end 28 (
Wear member 10 preferably includes a wear indicator depression 170 that opens in cavity 26 (
Locks 16 are preferably used to secure wear member 10 to base 12, and base 12 to nose 18 (
Lock 16 includes a mounting component or collar 222 and a retaining component or pin 220 (
Collar 222 has a cylindrical body 225 with lugs 236, 237 that project outward to contact and bear against bearing surfaces or shoulders 71, 73 of retaining structure 69 to hold lock 16 in place in wear member 10. To install collar 222, body 225 is inserted into hole 67 from within cavity 26 such that lugs 236, 237 is slid along passage or slot 75, and then rotated so that lugs 236, 237 straddle retaining structure 69 (
Once collar 222 is in place, a retainer or clip 224 is inserted into passage 75 from outside wear member 10 (
The engagement of lugs 236, 237 against shoulders 71, 73 mechanically hold collar 222 in hole 67 and effectively prevent inward and outward movement during shipping, storage, installation and/or use of wear member 10. A mechanical attachment is preferred because the hard, low alloy steel commonly used to manufacture wear members for earth working equipment generally lacks sufficient weldability. Collar 222 is preferably a single unit (one piece or assembled as a unit), and preferably a one piece construction for strength and simplicity. Retainer 224 is preferably formed of sheet steel as it does not resist the heavy loads applied during used. Retainer 224 is used only to prevent undesired rotation of collar 222 in hole 67 so as to prevent release of lock 16 from wear member 10.
Pin 220 includes a head 247 and a shank 249 (
Preferably, hex socket 248 is provided with a clearance opening 250 in place of one facet (i.e., only five facets 280 are provided), to define a cleanout region (
An additional benefit of a lobe-shaped cleanout region is that the combination of a hex socket with a lobe-shaped cleanout region on one facet of the hex socket also creates a multiple-tool interface for pin 20. For example, a hex socket sized for use with a ⅞-inch hex drive T (
In one preferred embodiment, threaded pin 220 includes a biased latching tooth or detent 252, biased to protrude beyond the surrounding thread 254 (
Further application of torque to pin 220 will squeeze latching detent 252 out of outer pocket 256. An inner pocket or recess 260 is formed at the inner end of the thread of collar 222. Preferably, the thread 258 of collar 222 ends slightly before inner pocket 260. This results in an increase of resistance to turning pin 220 as pin 220 is threaded into collar 222, when latching detent 252 is forced out of thread 258. This is followed by a sudden decrease of resistance to turning pin 220, as latching detent 252 aligns with and pops into the inner pocket. In use, there is a noticeable click or “thunk” as pin 220 reaches an end of travel within collar 222. The combination of the increase in resistance, the decrease in resistance, and the “thunk” provides haptic feedback to a user that helps a user determine that pin 220 is fully latched in the proper service position. This haptic feedback results in more reliable installations of wear parts using the present combined collar and pin assembly, because an operator is trained to easily identify the haptic feedback as verification that pin 220 is in the desired position to retain wear member 10 on base 12. The use of a detent 252 enables pin 220 to stop at the desired position with each installation unlike traditional threaded locking arrangements.
Preferably, latching detent 252 may be formed of sheet steel, held in place within a sump 262 within pin 220, resiliently fixed in place inside an elastomer 264. Sump 262 extends to open into cleanout region 250. The elastomer contained in sump 262 also may extend into cleanout region 250, when latching detent 252 is compressed during rotation of pin 220. Conversely, the elastomer contained in sump 262 forms a compressible floor for cleanout region 250, which may aid in the breakup and removal of compacted fines from cleanout region 250. Elastomer 264 may be molded around latching detent 252 so that elastomer 264 hardens in place and bonds to latching detent 252. The resulting subassembly of detent 252 and elastomer 264 may be pressed into place through cleanout region 250, and into sump 262. A preferred construction of latching detent 252 includes a body 266, a protrusion 268, and guide rails 270. Protrusion 268 bears against a wall of sump 262, which keeps latching detent 252 in proper location relative to thread 254. Guide rails 270 further support latching detent 252, while allowing compression of latching detent 252 into sump 262, as discussed above.
When pin 220 is installed into collar 222, it is rotated ½ turn to the release position for shipping, storage and/or installation of wear member 10. The wear member containing integrated lock 16 is installed onto nose 48 of base 12 (
Lock 16 is located within the upper recess 70 between side sections 56 for protection against contact with the ground and wear during use (
Pin 20 may be released using a ratchet tool or other tool to unscrew pin 220 from collar 222. While pin 220 can be removed from collar 222, it need only be backed up to the release position. Wear member 10 can then be removed from nose 48. The torque of unscrewing pin 220 may exert substantial torsion loads on collar 222, which loads are resisted by stops 77 and 79, providing a strong and reliable stop for lugs 236 and 237. [93] The mounting component 222 of lock 16 defines a threaded bore 223 for receiving a threaded securing pin 220 that is used to releasably hold wear member 10 to base 12 (and base 12 to adapter 19). The separate mounting component 222 can be easily machined or otherwise formed with threads, and secured within the wear member for less expense and higher quality threads as compared to forming the threads directly in the wear member. The steel used for wear member 10 are very hard and it is difficult to cast or otherwise form screw threads into hole 67 for the intended locking operation. The relatively large size of wear member 10 also makes it more difficult to cast or otherwise form screw threads in hole 67. The mounting component 222 can be mechanically held within the hole in the wear member to resist axial movement in either direction (i.e., that is in and out of hole 67) during use so as to better resist unintended loss of the lock during shipping, storage, installation and use. On account of the hard steel typically used for wear member 10, mounting component 222 could not be easily welded into hole 67. [94] The use of a lock in accordance with the present invention provides many benefits: (i) a lock integrated into a wear member so that the lock ships and stores in a ready to install position for less inventory and easier installation; (ii) a lock that requires only common drive tools such as a hex tool or ratchet driver for operation, and requires no hammer; (iii) a lock with easy tool access; (iv) a lock with clear visual and haptic confirmation of correct installation; (v) a new lock provided with each wear part; (vi) a lock that is positioned for easy access; (vii) a lock with a simple intuitive universally understood operation; (vii) a permanent mechanical connection between components of differing geometric complexity creates a finished product with features and benefits extracted from specific manufacturing processes; (viii) a lock integration system built around simple castable feature where the integration supports high loads, requires no special tools or adhesives and creates a permanent assembly; (ix) a lock with a hex engagement hole elongated on one facet allowing easier cleanout of soil fines with simple tools; (x) a lock located with a central part of the wear assembly to protect the lock from wear and reduce the risk of lock ejection; (xi) a lock with reaction lugs on the lock collar to carry system loads perpendicular to bearing faces; (xii) a retaining clip installed at the manufacturing source that holds the collar into the wear member while also biasing the collar against the load bearing interface and taking slack out of the system; (xiii) a design approach that simplifies casting complexity while supporting expanded product functionality; (xiv) a design approach whereby critical fit surfaces in the lock area need only be ground to fit one part which could act as a gage; and (xv) a design that fits within standard plant processes.
Lock 16 is a coupling arrangement for securing two separable components in an excavating operation. The system consists of a pin 220 received in a hole 66 in a base 12 and a collar 222 mechanically retained in the wear member 10. The collar contains features supportive of integrated shipment, load transmission, lock installation and lock removal. The collar is secured to the wear member with a retainer 224 which acts upon two lugs 236, 237 at the perimeter of the collar maintaining the lugs in an optimal load bearing orientation. The retainer also tightens the fit between components. The pin 220 helically advances through the center of the collar 222 between two low energy positions created by an elastomer backed latching mechanism. The first position keeps ½ turn of thread engaged between the collar and the pin for retention during shipment. The pin 220 advances into the second low energy position after rotating 2½ turns ending in a hard stop signaling that the system is locked. When the wear member 10 requires changing, the pin 220 is rotated counter-clockwise and removed from the assembly allowing the wear member to slide free from the base.
While the illustrated embodiment is an excavating tooth, the features associated with the locking of wear member 10 on base 12 can be used in a wide variety of wear assemblies for earth working equipment. For example, runners can be formed with a hole, like hole 67, and mechanically secured to a base defined on the side of a large bucket, a chute surface, a bed of a truck body and the like.
The disclosure set forth herein encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. Each example defines an embodiment disclosed in the foregoing disclosure, but any one example does not necessarily encompass all features or combinations that may be eventually claimed. Where the description recites “a” or “a first” element or the equivalent thereof, such description includes one or more such elements, neither requiring nor excluding two or more such elements. Further, ordinal indicators, such as first, second or third, for identified elements are used to distinguish between the elements, and do not indicate a required or limited number of such elements, and do not indicate a particular position or order of such elements unless otherwise specifically stated.
Number | Date | Country | |
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61507726 | Jul 2011 | US | |
61576929 | Dec 2011 | US |
Number | Date | Country | |
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Parent | 14838117 | Aug 2015 | US |
Child | 15984247 | US | |
Parent | 13547353 | Jul 2012 | US |
Child | 14838117 | US |